Method and apparatus for synchronous coupling of neutral fluid with plasma for refreshment

Abstract

This invention discloses a method and apparatus for synchronously coupling and updating neutral fluid and plasma, relating to the fields of fusion plasma simulation and multifluid coupling calculation technology. The method includes: reading the plasma stage state, neutral fluid state, neutral discrete carrier, transport envelope, and state equation configuration; forming ionization, recombination, and collisional exchange rates; forming a neutral-side update to be accepted based on the neutral transport flux and the same exchange rate; forming and connecting plasma-side exchange source terms; synchronizing the plasma and neutral state equations; and accepting or rejecting the update based on income and expenditure records and consistency acceptance. This avoids asynchrony between the neutral state, source terms, and state equations.

Description

Technical Field

[0001] This invention relates to the fields of fusion plasma simulation, multifluid coupling, reaction-collision source terms, and multiphysics closure solution, and particularly to a method and apparatus for synchronous coupling and updating of neutral fluid and plasma. Background Technology

[0002] In fusion device simulations, background neutral gas, wall-recirculated neutral particles, jet feed, and neutral particle injection interact with the plasma through ionization, recombination, charge exchange, elastic collisions, and energy exchange. If neutral particles are treated only for preset source parameters, changes in neutral density, velocity, and energy cannot be consistent with plasma-side particle, momentum, and energy source terms. If neutral fluid updates are accepted within a time sub-phase, while plasma-side source terms, equation of state synchronization, or magnetohydrodynamic updates are rejected, inconsistencies in particle budget, momentum exchange, and energy budget records will occur.

[0003] In related technologies, neutral fluid models can employ a conservation-type propulsion similar to that of plasma fluids, and couple with the plasma through ionization, recombination, charge exchange, and electron-neutral collisions. If such models are directly incorporated into a complete magnetohydrodynamic solver, neutral state propulsion, plasma source term access, state equation synchronization, and magnetic flux writing permissions can easily be mixed in the same implementation details, leading to unclear sub-boundaries. Rapid engineering simulation requires an independent neutral fluid coupling interface that allows the neutral-side pending update and the plasma-side exchanged source terms to be formed, accessed, and accepted within the same sub-stage.

[0004] Furthermore, neutral particle injection typically possesses both external engineering input attributes and particle, momentum, and energy deposition attributes. Radio frequency heating, current-driven processes, or anomalous transport closures can also alter plasma energy or non-ideal electric field terms. Radio frequency, electric field, electron cyclotron resonance, glow discharge, or seed electron sources during the pre-ionization phase serve as adaptation inputs before the main discharge, altering early electron energy distribution, initial charged particle states, or effective ionization rates. During repetitive pulse operation, residual neutral gas, residual electrons / ions, wall recirculation inventory, and temperature relaxation states following the previous pulse are inherited states across pulses, influencing the initial ionization and source term balance of the next pulse. If these objects lack a unified access boundary, the same source term can easily be repeatedly counted as both an external boundary input and an internal source term, or its magnetic flux state can be altered through unauthorized paths. Therefore, a neutral fluid and plasma synchronous coupling and updating method is needed that can distinguish between neutral fluid states, plasma-side exchanged source terms, state equation synchronization, source term balance recording, and magnetic flux writing permissions. Summary of the Invention

[0005] The purpose of this invention is to provide a method and apparatus for synchronous coupling and updating of neutral fluid and plasma, in order to solve the problems of asynchronous neutral state propulsion and plasma-side source term access, non-closed particle momentum-energy exchange budget record, asynchronous electron density or electroneutrality conditions, and neutral-related collision contributions bypassing the authorized magnetic update path.

[0006] The core constraint relationships of this invention include: the plasma stage state, neutral fluid state, neutral discrete carrier, neutral transport closure quantity, and neutral state equation closure quantity are read within the same time sub-stage; when there is a pre-ionization adaptation input or a cross-pulse inheritance state, the pre-ionization adaptation input or cross-pulse inheritance state is read as part of the synchronous coupling stage state; the same plasma stage state, neutral fluid state, state equation closure quantity, and reaction collision configuration jointly form the same ionization and collision exchange rate; the same exchange rate simultaneously forms the neutral-side pending acceptance update and the plasma-side particle, momentum, and energy exchange source terms; the neutral-side pending acceptance update is jointly formed by the neutral transport flux, neutral transport closure quantity, and reaction collision source terms; the plasma-side exchange source terms are accessed and triggered to resynchronize the plasma state equation and the neutral state equation through internal source term paths, right-hand term paths in the same stage, or operator splitting source term paths; the synchronization consistency acceptance is used to determine whether the neutral-side pending acceptance update, plasma-side exchange source terms, source term income and expenditure records, state equation synchronization results, and transport closure quantity are jointly accepted. The synchronization refers to the sharing of input state, exchange rate, and income and expenditure records among the aforementioned objects within the same acceptable time boundary. It does not require all sub-equations to be assembled into a single global matrix and solved simultaneously. Under the conditions of consistent income and expenditure and consistent acceptance, sequential sub-steps, operator splitting, prediction correction, local implicit or semi-implicit methods can be used to achieve this.

[0007] In this specification, the neutral fluid state refers to the state of neutral particles or molecular components synchronously coupled with the plasma state within the same time sub-phase. The neutral fluid state is based on the neutral number density and may include neutral velocity, neutral momentum, neutral energy, neutral temperature, neutral component fraction, background neutral gas state, wall recirculation state, jet boundary state, neutral particle injection beam state, pre-charged neutral state determined by pre-ionization adaptation input, or residual neutral state provided by cross-pulse inherited state. The neutral fluid state may be expressed according to neutral conservation variables, including neutral mass, neutral momentum, neutral energy, or neutral component mass fraction. The neutral fluid state does not include external constants used only as fixed coefficients and not forming neutral-side acceptance updates, nor does it include pre-ionization engineering configurations that have not been converted into neutral or charged particle states.

[0008] In this specification, the neutral discrete carrier refers to a spatially discrete object used to carry neutral fluid states and neutral transport fluxes. The neutral discrete carrier can use the same grid, control volume, geometric quantities, and discrete divergence operator as the plasma stage state; alternatively, it can use an independent neutral grid, beamline discretization, wall inventory discretization, jet boundary discretization, or a hybrid discretization. When the neutral discrete carrier is inconsistent with the discrete carrier of the plasma stage state, the neutral-side exchange quantity enters the plasma source term access module 108 through conservation mapping, projection, reconstruction, or volume overlap weighting, and the particle, momentum, and energy balance before and after mapping is checked in the synchronization consistency acceptance module 109.

[0009] In this specification, the neutral-plasma exchange rate refers to the reaction or collision rate formed based on the plasma state, neutral fluid state, and reaction-collision configuration. The neutral-plasma exchange rate includes one or more of the following: ionization rate, recombination rate, molecular binding rate, charge exchange rate, elastic collision rate, electron-neutral collision rate, or thermal equilibrium exchange rate. A common constraint on the above exchange rates is that the same exchange rate is used simultaneously for both the neutral-side acceptance update and the plasma-side exchange source term, and is not accepted as two separate sets of source terms.

[0010] In this specification, the electron collisional ionization rate refers to the ionization rate jointly determined by the electron energy pool, electron temperature, electron energy distribution function, and neutral particle reaction cross section. The electron collisional ionization rate can be formed using Maxwell's electron reaction rate lookup table, cross section integration, semi-empirical ionization formula, integration of the non-thermal electron energy distribution function, or experimentally calibrated parameterized model. The recombination rate refers to the rate at which charged particles transform into neutral particles or molecular states, determined by electron density, ion density, electron temperature, and recombination coefficient, including one or more of radiative recombination, three-body recombination, dissociative recombination, or molecular bonding. The induced electric field, radio frequency absorption power, or fast particle deposition power participates in the formation of the ionization rate by changing the electron temperature, electron energy pool, non-thermal electron tail, or effective ionization rate; the external magnetic field or the magnetic field derived from the flux state is only used to form modulation inputs such as connection length, constraint time, anisotropic transport, deposition distribution, or boundary loss coefficient, and is not used as a direct ionization source.

[0011] In this specification, the effective ionization potential refers to the equivalent energy amount deducted from or added to the loss balance record for each electron-ion pair formed. The effective ionization potential can be determined jointly by the ionization threshold energy of the neutral component, the energy loss from electron collision excitation levels, the energy loss from electron-neutral elastic scattering, the radiation escape hypothesis, and electron temperature-related lookup data or experimental calibration fitting. The effective ionization potential does not change the stoichiometry of particle exchange; rather, it is used to ensure that the electron energy loss, excitation radiation loss, and low-temperature pre-ionization energy consumption during the ionization process are included in the same energy balance record.

[0012] In this specification, the neutral transport closure quantity refers to the neutral viscosity, volume viscosity, neutral thermal conductivity, component diffusion coefficient, wall conditioning coefficient, or boundary loss coefficient used when forming the neutral transport flux. The neutral transport closure quantity is input using neutral temperature, neutral density, neutral component fraction, pressure, or relative velocity, and can be determined through Chapman-Enskog models, Sutherland-type temperature laws, reaction rate or transport coefficient lookup tables, multi-component mixing rules, offline particle simulation, direct simulation Monte Carlo models, experimental calibration parameters, or constant closures. The common output of the above closure methods is the transport coefficient usable by the neutral transport flux; if the transport coefficient changes with temperature, density, or component variations within a time sub-stage, the change should be written into the transport closure quantity check item of the synchronization consistency acceptance module 109.

[0013] In this specification, the neutral equation of state refers to a closure relation that outputs neutral pressure, neutral temperature, neutral velocity of sound, neutral enthalpy, neutral internal energy, heat capacity ratio, or adoptability indicator based on neutral density, neutral component fraction, neutral energy, or neutral temperature. The neutral equation of state can be a monatomic neutral ideal gas equation of state, a multi-component mixed gas equation of state, a molecular neutral equation of state including rotational degrees of freedom, vibrational degrees of freedom, or dissociation energy, a lookup table equation of state, an experimentally calibrated equation of state, or a low-order isothermal closure. The neutral equation of state does not replace the plasma equation of state; after the source term is connected, both the plasma equation of state and the neutral equation of state should be re-called according to their respective states and jointly checked by the synchronization consistency acceptance module 109.

[0014] In this specification, pre-ionization adaptation input refers to external inputs, initial quantities, or model configurations used to form seed electrons, early electron energy distribution, or initial ionization rate before the main plasma discharge or main heating stage. The pre-ionization adaptation input includes one or more of the following: radio frequency pre-ionization, electron cyclotron resonance pre-ionization, induced electric field pre-ionization, glow discharge pre-ionization, seed electron source, pre-charged neutral number density, pre-charged neutral temperature, initial electron temperature, initial electron energy distribution function, initial ionization fraction, pre-ionization time window, or pre-ionization deposition distribution. The pre-ionization adaptation input is not considered as an independent neutral fluid state itself; it only enters the ionization and collision rate formation module 103 or the coupling state reading module 101 through electron temperature, electron energy distribution function, effective ionization rate, or initial charged particle state. The portion already counted as the initial charged particle state is not counted again as an internal particle source and is not directly written into the magnetic flux state.

[0015] In this specification, a cross-pulse inherited state refers to a historical state derived from the state after acceptance of the previous pulse or the evolution result of the intermittent sub-stage during repeated pulse operation, which continues to participate in synchronous coupling in the next pulse. The cross-pulse inherited state includes one or more of the following: residual neutral density, residual electron density, residual ion density, residual electron temperature, residual ion temperature, wall recirculation inventory, gas supply history, evacuation or venting state, intermittent duration, neutral temperature relaxation state, electron / ion temperature relaxation state, or source term income and expenditure records after acceptance of the previous pulse. These states are not new external stimuli, and their boundary constraints include nonnegativity, boundary loss, particle income and expenditure, energy income and expenditure, and wall inventory consistency; they should be accepted by the synchronous consistency acceptance module 109 before being written into the next pulse or the next time sub-stage.

[0016] In this specification, plasma-side exchange source terms refer to particle exchange source terms, momentum exchange source terms, or energy exchange source terms formed by the neutral-plasma exchange rate and updated in the plasma stage. These plasma-side exchange source terms can enter internal source term paths, right-hand term paths within the same stage, or operator-split source term paths; they do not include the processing of directly rewriting the flux state around the open source term income and expenditure record.

[0017] In this specification, the neutral-side update awaiting acceptance refers to a neutral update formed by the neutral fluid state, neutral transport flux, neutral transport envelope, and neutral-plasma exchange rate, which has not yet been written into the state of the next time sub-stage. The neutral-side update awaiting acceptance includes a neutral number density update, and may also include a neutral momentum update, a neutral energy update, a neutral temperature update, or a molecular neutral component update. The neutral-side update awaiting acceptance is only accepted after the synchronization and consistency acceptance is passed.

[0018] In this specification, synchronization consistency acceptance refers to the process of jointly checking the neutral-side update to be accepted, the plasma-side exchanged source terms, the synchronization results of the equation of state, the neutral transport envelope, and the source term balance records within the same time sub-phase. The synchronization consistency acceptance includes particle balance checks, electrically neutral or electron density consistency checks, momentum exchange checks, energy balance checks, neutral state positivity checks, neutral equation of state adoptability checks, neutral transport envelope change checks, source term balance record checks, and flux write permission checks.

[0019] In this specification, the authorized magnetic update drive path refers to the authorized entry point that must be passed through when a non-ideal electric field, resistivity correction, effective collision frequency correction, or external electromagnetic response enters the magnetic update process. The contribution of electron-neutral collisions to resistivity, effective collision frequency, or non-ideal electric field can be used as input to the authorized magnetic update drive path, but it must not be directly written into the magnetic flux state, surface magnetic flux, edge electric field circulation, or magnetic update residual. In one implementation, the electron-neutral collision frequency, electron-ion collision frequency, and anomalous collision frequency together form the resistivity or magnetic diffusion coefficient; the aforementioned resistivity or magnetic diffusion coefficient is only used as input to the formation of the non-ideal electric field or magnetic update drive quantity and is subject to magnetic flux write permission checks.

[0020] In one implementation, the method first reads plasma mass, momentum, energy, electron density or electrically neutral constraint, neutral fluid state, neutral discrete carrier, geometric state, magnetic field derived from the flux state, reaction collision configuration, neutral transport closure, and neutral state equation closure through the coupling state reading module 101. The neutral state management module 102 organizes the neutral fluid state into neutral conserved variables, as shown in Equation 1:

[0021] In Equation 1, U n Let ρ represent a neutral, conserved variable. n U represents neutral mass density. n E represents neutral velocity. n U represents the neutral energy density, and the mass fraction of each component is defined by the neutral component index s. For low-order embodiments that do not solve for neutral momentum or neutral energy properties, U n It can degenerate into a neutral number density and a neutral temperature. The degenerated state still needs to enter the synchronous consistency acceptance module 109.

[0022] The neutral discrete carrier can share the control volume and discrete divergence operator with the plasma stage state, or it can be discretized using an independent grid or bundle line. When an independent neutral discrete carrier is used, the neutral-side commutatives enter the plasma-side source term path through the mapping operator, as shown in Equation 2:

[0023] In Equation 2, S n S represents the amount of particle, momentum, or energy exchanged on a neutral discrete carrier. p The source term is represented after mapping to the plasma discrete carrier. The neutral-to-plasma mapping operator represents the conserved mapping, projection, reconstruction, or volume overlap weighting operator. The mapping balance residual is entered into the synchronization consistency acceptance module 109 as part of the particle, momentum, or energy balance check.

[0024] In one implementation, the neutral-side update module 107 generates a neutral-side update to be accepted based on the neutral transport flux and the reaction collision source term, as shown in Equation 3:

[0025] In Equation 3, the neutral conserved variable with the wavy line represents the state to be accepted; the discrete divergence operator on the neutral discrete carrier acts on the neutral convection or pressure flux and the neutral transport flux; the neutral transport flux is determined by the neutral viscosity μ. n Neutral thermal conductivity κ n and component diffusion coefficient D n Formation occurs through reaction collisions, which are formed by ionization, recombination, molecular bonding, charge exchange, elastic collisions, and electron-neutral collisions; boundary source terms are formed by jetting, wall recirculation, pumping, boundary loss, or beam neutral deposition. These updates can be implemented explicitly, implicitly, semi-implicitly, via operator splitting, or via sub-iteration, but their outputs are always pending acceptance states rather than the next state to be written immediately.

[0026] The neutral transport closure can be recalculated from the current state in each time sub-stage, as shown in Equation 4:

[0027] Formula 5:

[0028] In Equations 4 and 5, the three closure operators are used to calculate neutral viscosity, neutral thermal conductivity, and component diffusion coefficient, respectively. Their implementation can include the Chapman-Enskog model, Sutherland-type temperature law, transport coefficient lookup table, multi-component mixing rule, offline particle simulation, direct simulation Monte Carlo model, experimental calibration parameter or constant closure. The wavy viscosity in Equation 5 is the neutral viscosity recalculated from the state to be accepted, and the change represents the change in neutral viscosity. If the change in neutral viscosity, thermal conductivity, or diffusion coefficient exceeds the threshold, the synchronous consistency acceptance module 109 outputs a decision to recalculate the transport flux, execute a sub-iteration, adopt implicit update, reduce the time step, or reject the current time sub-stage.

[0029] The ionization and collision rate formation module 103 forms ionization, recombination, charge exchange, elastic collision, electron-neutral collision, or thermal equilibrium exchange rates based on the electron energy pool, electron temperature, ion temperature, neutral temperature, relative velocity, cross-sectional data, reaction rate table, or electron energy distribution function. The electron collision ionization rate and recombination rate can be written as shown in Equation 6:

[0030] Formula 7:

[0031] In equations 6 and 7, n e Electron density, neutral component fraction density, and corresponding ion component fraction density are all defined according to the component number 's'; ionization cross section, ionization reaction rate coefficient, and recombination coefficient are also defined according to the component number 's'; f e This represents the electron energy distribution function. The Maxwell electron reactivity lookup table is the realization of Equation 6 under the Maxwell distribution; the nonthermal electron energy distribution function integral, Lotz-type semi-empirical formula, or experimentally calibrated parameterized model all take the electron energy distribution or effective electron temperature as input and output the ionization reactivity coefficient. The recombination coefficient can include radiative recombination, three-body recombination, dissociative recombination, molecular bonding, or lookup table recombination.

[0032] The charge exchange rate can be written as shown in Equation 8:

[0033] In Equation 8, the load exchange rate, effective load exchange velocity, and load exchange cross section are all defined according to the component number s; the load exchange cross section can be obtained according to the effective load exchange velocity, relative energy, or by looking up a table index, uᵢ and u n These represent ion velocity and neutral velocity, respectively. The charge-exchange momentum exchange term can be formed into a pair of terms based on particle mass, charge-exchange rate, and relative velocity, and these terms are entered into the plasma side and neutral side, respectively. The charge-exchange heat exchange term can be formed based on ion temperature, neutral temperature, and relative velocity, and written into the energy budget record. The charge-exchange closure can also employ modified thermal velocities, experimental cross-sections, or multi-component mixing rules. All of the above closure methods use the same neutral fluid state and plasma stage state as inputs, and ensure that the neutral side and plasma side use the same exchange rate.

[0034] For time sub-stages with strong rigidity in ionization and recombination reactions, particle exchange closure module 104 can first perform non-reaction-free transport propulsion, and then perform reaction-conserving implicit propulsion within each control volume or mapped local reaction unit. For a single neutral component and its corresponding ionic component, the local reaction step can be represented by the following relationship, as shown in Equation 9:

[0035] In Equation 9, nᵢ represents the corresponding ion number density, n nThe neutral number density, electron collision ionization reaction rate coefficient, and recombination coefficient control the ionization gain term and recombination loss term, respectively. When the electron density or electron neutrality relationship is given by the current local state, implicit discretization can form an algebraic equation regarding the change in particle number; in the implementation of a monovalent single component with conserved total mass particle number, this algebraic equation can degenerate into a quadratic equation. The obtained change in particle number is used to update both the neutral number density and the charged particle number density, and the local total particle number residual is written into the synchronization consistency acceptance module 109. For multi-component molecular reaction networks, small local nonlinear equation sets, Newton iteration, table-driven implicit updates, or sub-loop methods can be used to form the update of the reaction to be accepted.

[0036] The particle exchange closure module 104 generates neutral-side particle change and plasma-side particle exchange source terms based on ionization, recombination, and molecular reaction exchange rates. The momentum exchange closure module 105 generates momentum exchange source terms based on charge exchange, elastic collisions, or neutral resistance, and ensures that the momentum exchange on the neutral and plasma sides corresponds to each other in the discrete budget record. The energy exchange closure module 106 generates energy exchange source terms based on effective ionization potential, recombination radiation, charge exchange, elastic collisions, electron-neutral collisions, or thermal equilibrium processes, and writes them into the ion energy pool, electron energy pool, neutral energy pool, radiation loss budget record, or source term budget record, respectively.

[0037] In one implementation, the effective ionization potential can be formed according to electron temperature, reaction rate, and energy level loss, as shown in Equation 10:

[0038] In Equation 10, the effective ionization potential and ionization threshold energy are defined according to the neutral component index s; the reaction rate and excitation energy of the electron collision excitation channel are defined according to the excitation channel index j; the electron-neutral elastic scattering reaction rate and the equivalent electron energy loss function are used to represent the electron energy loss caused by elastic scattering. If the optical thin approximation is used, the excited state radiation energy can be written into the radiation loss budget record; if the radiation capture or reabsorption model is used, the corresponding energy is returned to the electron energy pool, neutral energy pool, or radiation pool according to the model configuration. The role of the effective ionization potential is to correct the electron energy budget without changing the particle stoichiometry of the ionization rate.

[0039] The electron-neutral collision frequency can be used as the resistivity closure input, as shown in Equation 11:

[0040] In Equation 11, η represents resistivity, m eη represents the electron mass, e represents the elementary charge, and the three terms in parentheses represent the electron-ion collision frequency, electron-neutral collision frequency, and anomalous collision frequency, respectively. The anomalous collision frequency can be given by Chodura-type, Bohm-type, gyro-Bohm-type, experimental calibration, or model configuration. η only enters the non-ideal electric field term or magnetic diffusion term in the authorized magnetic update drive path and is not used as the entry point for directly writing the magnetic flux state in modules 101 to 109.

[0041] In one implementation, the neutral equation of state outputs neutral pressure, temperature, speed of sound, and an admissibility flag from the neutral state. For a monatomic ideal neutral gas, it can be used, as in Equation 12:

[0042] In Equation 12, γ n The neutral heat capacity ratio is represented by the Boltzmann constant, which is used to recover the neutral temperature from pressure and number density. For molecularly neutral or multi-component neutral states, the equation of state may further include rotational degrees of freedom, vibrational degrees of freedom, dissociation energy, mixing heat capacity, or lookup table internal energy. The plasma source term access module 108 re-invokes the plasma equation of state and the neutral equation of state after source term access to synchronize electron density, pressure, temperature, sound velocity, neutral transport envelope, and acceptability flag.

[0043] Neutral boundary states can be categorized by physical source into inlet boundary, wall boundary, opening loss boundary, and inventory boundary. The inlet boundary is used to represent a given jet, pre-charge, beam neutrality, or external background neutrality. The wall boundary represents reflection, adsorption, re-emission, wall recirculation, thermal adaptation, or wall temperature regulation. The opening loss boundary represents pumping, end escape, or free outflow. The inventory boundary stores the number of adsorbed particles on the wall, recirculation delay, residual neutral inventory from the previous pulse, or relaxation state during the interval. These boundaries can be implemented using Dirichlet states, Neumann flux, Robin flux, reflection coefficient, recirculation coefficient, adsorption inventory equation, or lookup table boundary models. A common constraint is that the contributions of boundary particles, momentum, and energy must be entered into the source term budget record and accepted or rejected together with the neutral-side update to be accepted in the synchronous consistency acceptance module 109.

[0044] The synchronization consistency acceptance module 109 checks the particle, momentum, energy, positivity, acceptability of the equation of state, changes in transport closure, source term income and expenditure records, and magnetic flux write permissions, and outputs a decision to accept, recalculate, shorten the time step, or reject the current time sub-stage. Through this scheme, the neutral fluid state is no longer just an external parameter, but is formed within the same time sub-stage by transport flux, reaction collision source terms, and the equation of state, and is subject to acceptance updates; plasma-side exchange source terms are no longer accepted separately from the neutral-side state, but are accepted synchronously with the equation of state, along with transport closure and source term income and expenditure records; contributions from electron-neutral collisions that may affect the non-ideal electric field are also limited to authorized paths, thus avoiding unauthorized magnetic flux writes. Attached Figure Description

[0045] Figure 1 This diagram illustrates the overall architecture of the synchronous coupling of neutral fluid and plasma according to an embodiment of the present invention.

[0046] Figure 2 A flowchart illustrating the formation of ionization and collision exchange rates according to an embodiment of the present invention is shown.

[0047] Figure 3 This diagram illustrates the relationship between the neutral side pending acceptance update and the plasma source term access in an embodiment of the present invention.

[0048] Figure 4 The flowchart of the synchronization consistency acceptance process according to an embodiment of the present invention is shown.

[0049] Figure 5 This diagram illustrates the pre-ionization adaptation, cross-pulse inheritance, and neutral source extension relationships according to an embodiment of the present invention. Detailed Implementation

[0050] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The described embodiments are only some embodiments of the present invention, and not all embodiments; other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the protection scope of the present invention.

[0051] Figure 1The overall architecture for synchronous coupling of neutral fluid and plasma is shown. The coupling state reading module 101 reads the plasma stage state, neutral fluid state, neutral discrete carrier, geometric state, magnetic field derived from the flux state, transport envelope, and time sub-stage information. The neutral state management module 102 stores the neutral number density, neutral velocity, neutral momentum, neutral energy, neutral temperature, neutral discrete carrier, neutral transport envelope, or neutral equation of state envelope, and uses these as the source of the neutral state to be accepted. The ionization and collision rate formation module 103 forms the neutral-plasma exchange rate based on the equation of state envelope, relative velocity, and reaction collision configuration. The particle exchange closure module 104, momentum exchange closure module 105, and energy exchange closure module 106 respectively form plasma-side exchange source terms. The neutral-side update module 107 forms the neutral-side update to be accepted based on the neutral transport flux, boundary flux, and reaction collision source terms. The plasma source term access module 108 accesses the plasma-side exchange source term and triggers resynchronization of the plasma state equation and neutral state equation. The synchronization consistency acceptance module 109 determines whether the current time sub-stage is accepted.

[0052] Figure 2 The process of forming the ionization and collision exchange rate is illustrated. After the coupling state is read, the ionization and collision rate forming module 103 can form the exchange rate using cross-sectional integration, lookup table reaction rate, semi-analytical formula, integration of the non-thermal electron energy distribution function, or parameterized closure. If a lookup table reaction rate is used, the lookup index can include electron temperature, ion temperature, neutral temperature, electron density, neutral density, and relative velocity; if a parameterized closure is used, the parameters can be obtained from experimental calibration, offline particle simulation, direct simulation Monte Carlo model, or hybrid particle simulation. The common output of different reaction rate forming methods is the same neutral-plasma exchange rate that can be used on both the neutral side and the plasma side.

[0053] In one embodiment, the ionization process reduces the neutral number density and increases the charged particle number density, while consuming electron energy or recording the effective ionization potential. The recombination process reduces the charged particle number density and increases the neutral number density, while resulting in recombination energy release or radiation loss. The charge exchange process can exchange momentum and energy between plasma ions and neutral particles while maintaining particle number conservation. Elastic collisions and electron-neutral collisions can create drag terms, heat exchange terms, effective collision frequencies, or resistivity corrections. All of the above processes are recorded in the source term balance record for inspection by the synchronization consistency acceptance module 109.

[0054] Figure 3The relationship between the neutral-side update to be accepted and the plasma source term access is shown. The neutral-side update module 107 generates the neutral number density, neutral momentum, neutral energy, and neutral component fraction to be accepted based on the neutral transport flux, neutral transport envelope, and neutral-side exchange quantity. The plasma source term access module 108 selects the entry method according to the model configuration: 1. Enter the conserved fluid update quantity as a right-hand term in the same stage; 2. Enter the internal source term substep by splitting the source term path with an operator; 3. Execute half-steps before and after the magnetohydrodynamic flux solution using a time-symmetric splitting method. Figure 3 In this context, N6 represents the right-hand term path in the same stage, and N7 represents the split source term path. Regardless of the entry method, only one plasma-side source term access method is allowed within the same time sub-stage for the same neutral-plasma exchange rate. When the neutral discrete carrier differs from the plasma discrete carrier, the plasma source term access module 108 also performs conservation mapping or projection and records the mapping balance residuals.

[0055] In one embodiment, the external beam parameters for neutral particle injection are provided by boundary inputs or engineered inputs, including beam energy, beam angle, beam power, injection window, or beamline state. Particle, momentum, and energy exchange terms formed during beam propagation, ionization, charge exchange, and deposition enter the exchange source term link in this embodiment. In this way, neutral particle injection preserves the external input boundary without bypassing the neutral-plasma exchange rate formation process with deposited source terms.

[0056] In one embodiment, the pre-ionization adaptation input is read before the main discharge time sub-stage. The coupling state reading module 101 reads the RF pre-ionization power, electron cyclotron resonance pre-ionization power, induced electric field intensity, glow discharge configuration, seed electron density, pre-charged neutral density, initial electron temperature, initial electron energy distribution function, initial ionization fraction, pre-ionization time window, or pre-ionization deposition distribution. The ionization and collision rate forming module 103 corrects the electron temperature, electron energy distribution function, or effective ionization rate based on the above inputs, and forms the neutral-side pending update and plasma-side particle source terms. This pre-ionization adaptation input is not used as a flux state write path; portions already written as initial charged particle states are not repeatedly counted as internal particle sources.

[0057] In one embodiment, the intervals between repetitive pulse runs are treated as one or more time sub-stages. The coupling state reading module 101 reads the residual neutral density, residual electron / ion density, residual electron / ion temperature, wall recirculation inventory, gas supply history, evacuation or venting status, interval duration, radiative cooling status, temperature relaxation status, or source term balance record after the previous pulse acceptance. The ionization and collision rate forming module 103 forms recombination, reionization, charge exchange, elastic collision, or thermal equilibrium exchange rates. The synchronization consistency acceptance module 109 checks the consistency of the inter-pulse particle balance, energy relaxation, boundary loss, wall inventory, and the initial state of the next pulse. In this way, the residual gas and wall memory between repetitive pulses do not directly overwrite the synchronization coupling state as initial conditions without balance records.

[0058] In one embodiment, molecular neutrality extension is used to process multi-component reaction networks including deuterium atoms, deuterium molecules, deuterium ions, deuterium molecular ions, trideuterium molecular ions, and electrons. Molecular neutrality extension can first maintain the molecular neutral component states in the neutral state management module 102, and then the ionization and collision rate formation module 103 can generate dissociation, ionization, recombination, or molecular ion conversion exchange rates. The output of this reaction network is still aggregated to the particle exchange source term, momentum exchange source term, and energy exchange source term, without changing the interface between the plasma source term access module 108 and the synchronization consistency acceptance module 109.

[0059] Figure 4 The synchronization consistency acceptance process is shown. Figure 4 In this context, V1 represents particle budget check, V2 represents electrical neutrality check, V3 represents momentum-energy check, V4 represents equation of state and transport check, V5 represents the accept path, and V6 represents the reject path. The synchronization consistency acceptance module 109 can calculate particle budget residuals to check if ionization, recombination, and charge exchange correspond on the neutral and plasma sides; calculate electrical neutrality or electron density consistency errors to check if the electron density after source term access is compatible with the charged species state; calculate momentum exchange residuals and energy budget errors to check if collision exchanges have entered the correct energy pool and budget record; calculate neutral state positivity and neutral equation of state acceptability to check if neutral number density, temperature, pressure, or energy are acceptable; calculate changes in neutral transport closure quantity to check if changes in neutral viscosity, thermal conductivity, or diffusion coefficient require recalculation or step reduction; and calculate magnetic flux write permission errors to confirm that neutral-related source terms have not been directly written to the magnetic flux state, surface magnetic flux, edge electric field circulation, or magnetic update residuals.

[0060] Upon successful acceptance, the neutral side pending acceptance update, plasma side exchanged source term access results, state equation synchronization results, neutral transport closure quantity, and source term income and expenditure records are all written to the next time sub-stage state. If acceptance fails, the above objects remain in an unaccepted state. The system can recalculate the exchange rate, recalculate the neutral transport flux, shorten the time step, switch the reaction rate closure, switch the transport closure, reduce the source term sub-step size, execute a sub-iteration, or reject the current time sub-stage based on the failure type. In this way, neutral fluid updates and plasma source term access remain consistent at the acceptance point.

[0061] Figure 5 The pre-ionization adaptation, cross-pulse inheritance, and neutral source extension relationships are shown. Figure 5 In this context, N1 represents background neutral gas, N2 represents neutral particle injection, N3 represents molecular neutral expansion, N4 represents pre-ionization adaptation input, and N5 represents cross-pulse inheritance state. N1 can be provided by initial gas filling, wall recirculation, or jet boundary; N2 can be provided by beam input; N4 can be provided by radio frequency, electron cyclotron resonance, induced electric field, glow discharge, seed electron source, initial electron energy distribution, or pre-ionization deposition distribution; N5 can be provided by residual neutrality after the previous pulse acceptance, residual charged particles, wall recirculation inventory, gas supply history, boundary loss, and temperature relaxation state; N3 can provide a multi-component reaction network. Although the above objects have different physical sources, they are all uniformly converted into exchange rates by the ionization and collision rate forming module 103, and the deposition and exchange source terms are output by the plasma source term input module 108.

[0062] This invention also provides a device for synchronous coupling and updating of neutral fluid and plasma. The device includes a coupling state reading module 101, a neutral state management module 102, an ionization and collision rate formation module 103, a particle exchange closure module 104, a momentum exchange closure module 105, an energy exchange closure module 106, a neutral side update module 107, a plasma source term access module 108, and a synchronization consistency acceptance module 109. The neutral state management module 102 stores the neutral discrete carrier, the neutral transport closure quantity, and the neutral state equation closure quantity; the neutral side update module 107 forms the neutral transport flux and the neutral side update to be accepted; the plasma source term access module 108 performs source term access, conservation mapping, and state equation synchronization; the synchronization consistency acceptance module 109 checks the adoptability of the neutral state equation, changes in the neutral transport closure quantity, and magnetic flux write permissions. Modules 101 to 109 can be implemented by software functions, simulation framework components, graphics processor kernel functions, central processing unit threads, accelerator card tasks, or distributed computing nodes.

[0063] In one possible implementation, the electronic device includes a processor and a memory, the memory storing processor-executable instructions. When the processor executes the instructions, it invokes the functions corresponding to the coupling state reading module 101, neutral state management module 102, ionization and collision rate formation module 103, particle exchange closure module 104, momentum exchange closure module 105, energy exchange closure module 106, neutral side update module 107, plasma source term access module 108, and synchronization consistency verification module 109 to realize the above-mentioned neutral fluid and plasma synchronous coupling update method.

[0064] In some embodiments, a computer-readable storage medium stores computer program instructions that, when executed by a processor, implement the coupling state reading, ionization and collision rate formation, neutral transport flux formation, neutral-side pending acceptance update, plasma-side exchanged source term formation, source term access, state equation resynchronization, and synchronization consistency acceptance steps in the above method.

[0065] The present invention also provides a computer program product. The computer program product includes a computer program or instructions, which, when executed by a processor, cause an electronic device to perform the above-described method. The deployment forms of the computer program product include simulation software plug-ins, local program packages, container images, cloud tasks, or cluster job scripts.

Claims

1. A method for synchronous coupling and updating of neutral fluid and plasma, characterized in that, The process includes the following steps: S1. Reading the state of the synchronous coupling stage, which includes the plasma stage state, neutral fluid state, neutral discrete carrier, geometric state, magnetic field derived from the flux state, plasma equation of state closure, neutral equation of state closure, neutral transport closure, reaction collision configuration, and time sub-stage information, as well as pre-ionization adaptation input, cross-pulse inherited state, induced electric field, RF absorption power, or fast particle deposition power when present; S2. Forming ionization and collision exchange rates based on the same plasma stage state, neutral fluid state, and reaction collision configuration, and forming electron collision ionization rate, recombination rate, molecular binding rate, charge exchange rate, elastic collision rate, electron-neutral collision rate, or thermal equilibrium exchange rate based on electron energy pool, electron temperature, electron energy distribution, ion temperature, neutral temperature, relative velocity, cross-sectional data, reaction rate table, parameterized closure, induced electric field correction, RF absorption correction, fast particle deposition correction, or constraint parameters derived from the magnetic field; S3. S1. Form neutral-side pending updates: Based on the neutral discrete carrier, neutral conservation variables, neutral transport flux, neutral transport envelope, and the ionization and collision exchange rate, form neutral number density, neutral momentum, neutral energy, neutral temperature, or neutral component fraction pending updates. When the reaction rigidity exceeds the threshold, local reaction conservation implicit updates or sub-iterative updates are used. S4. Form plasma-side exchange source terms: Based on the same ionization and collision exchange rate, form plasma-side particle exchange source terms, momentum exchange source terms, and energy exchange source terms. S5. Connect plasma source term paths: Connect plasma-side exchange source terms to internal source term paths, right-end term paths of the same stage, or operator split source term paths to form source term income and expenditure records, and trigger the synchronization of the state equation envelope in step S6. S6. Synchronize the state equation envelope: After the source terms are connected, re-call the plasma state equation and the neutral state equation to synchronize electron density, ion temperature, electron temperature, neutral temperature, pressure, sound velocity, neutral transport envelope, or acceptability flag. S7. Perform synchronization and consistency acceptance. Based on particle budget residuals, electrical neutrality or electron density consistency, momentum exchange residuals, energy budget error, neutral state positivity, neutral state equation acceptability, neutral transport closure change, source term budget records, magnetic flux write permissions, and optional time step rigidity indicators, jointly accept the neutral side pending acceptance update, plasma side exchanged source terms, state equation synchronization results, and source term budget records, or recalculate, shorten the time step, or reject the current time sub-stage.

2. The method according to claim 1, characterized in that, The neutral discrete carrier uses the same grid, control volume, geometric quantities, and discrete divergence operator as the plasma stage state, or uses an independent neutral grid, beamline discretization, wall inventory discretization, or hybrid discretization. When the neutral discrete carrier is different from the discrete carrier of the plasma stage state, the neutral-side exchange quantity is mapped to the plasma-side source term path through conservation mapping, projection, reconstruction, or volume overlap weighting, and the particle number, momentum, and energy before and after the mapping are checked and accepted.

3. The method according to claim 1, characterized in that, The neutral-side acceptance update uses neutral-conserved variables as the update objects. The neutral-conserved variables include one or more of neutral mass, neutral momentum, neutral energy, or neutral component mass fraction. The neutral transport flux includes one or more of convective flux, pressure flux, viscous flux, thermal conduction flux, component diffusion flux, wall recirculation flux, jet boundary flux, or bundle neutral deposition flux. The neutral-side acceptance update can be formed using explicit, implicit, semi-implicit, operator splitting, local reaction conservation implicit solution, or sub-iteration methods.

4. The method according to claim 1, characterized in that, The electron collision ionization rate is formed by electron density, neutral number density, and electron collision ionization reaction rate coefficient. The electron collision ionization reaction rate coefficient is formed by one or more of the following: Maxwell's electron reaction rate lookup table, cross-sectional integral, Lotz-type semi-empirical ionization formula, non-thermal electron energy distribution function integral, or experimentally calibrated parameterized model. The recombination rate is formed by electron density, ion density, and recombination coefficient. The recombination coefficient includes one or more of the following: radiation recombination coefficient, three-body recombination coefficient, dissociation recombination coefficient, molecular binding rate coefficient, reaction rate lookup table, or experimentally calibrated parameter. The induced electric field, radio frequency absorption power, or fast particle deposition power participate in the formation of ionization rate by modifying electron temperature, electron energy distribution function, electron energy pool, or effective ionization rate. The effective ionization potential is jointly determined by ionization threshold energy, electron collision excitation loss, electron-neutral elastic scattering loss, or lookup table parameters. The external magnetic field or the magnetic field derived from the magnetic flux state is only used as a modulation input for connection length, constraint time, anisotropic transport, deposition distribution, or boundary loss coefficient, and is not used as a direct ionization source.

5. The method according to claim 1, characterized in that, The neutral transport envelope includes one or more of the following: neutral viscosity, neutral thermal conductivity, component diffusion coefficient, bulk viscosity, wall regulation coefficient, or boundary loss coefficient. The neutral transport envelope is determined using one or more of the following methods: Chapman-Enskog model, Sutherland-type temperature law, reaction rate or transport coefficient lookup table, multi-component mixing rule, offline particle simulation, direct simulation Monte Carlo model, experimental calibration parameter, or constant envelope. Neutral temperature, neutral density, neutral component fraction, pressure, or relative velocity are used as inputs. When the change in the neutral transport envelope exceeds a threshold in the current time sub-stage, the following actions are performed: recalculate transport flux, sub-iteration, implicit update, reduce time step, or reject the current time sub-stage.

6. The method according to claim 1, characterized in that, The neutral equation of state adopts one or more of the following: a monatomic neutral ideal gas equation of state, a multi-component mixed gas equation of state, a molecular neutral equation of state containing rotational degrees of freedom, vibrational degrees of freedom, or dissociation energy, a lookup table equation of state, an experimentally calibrated equation of state, or a low-order isothermal closure; the neutral equation of state accepts neutral density, neutral component fraction, neutral energy, or neutral temperature as input, and outputs one or more of the following: neutral pressure, neutral temperature, neutral speed of sound, neutral enthalpy, neutral internal energy, heat capacity ratio, or adoptability indicator.

7. The method according to claim 1, characterized in that, The momentum exchange source terms formed by charge exchange or elastic collisions are formed based on plasma velocity, neutral velocity, relative velocity, effective charge exchange velocity, collision cross section, and exchange rate, and enter the neutral-side pending update and plasma-side momentum exchange source terms with opposite signs; the energy exchange source terms include one or more of the following: temperature-related effective ionization potential consumption, recombination energy release, recombination radiation, charge exchange energy exchange, elastic collision heat exchange, electron-neutral collision energy exchange, or thermal equilibrium energy exchange; electron-neutral collision frequency, resistivity correction, or non-ideal electric field correction enter the magnetic update only through the authorized magnetic update drive path; when there is a pre-ionization adaptation input or cross-pulse inheritance state, the pre-ionization adaptation input and cross-pulse inheritance state enter steps S1 to S7 through electron temperature, electron energy distribution function, effective ionization rate, initial charged particle state, neutral boundary state, or neutral fluid state, and enter the source term income and expenditure record, without forming an independent internal particle source.

8. A device for synchronous coupling and renewal of neutral fluid and plasma, characterized in that, The system includes a coupling state reading module 101, a neutral state management module 102, an ionization and collision rate formation module 103, a particle exchange closure module 104, a momentum exchange closure module 105, an energy exchange closure module 106, a neutral side update module 107, a plasma source term access module 108, and a synchronization consistency acceptance module 109. The coupling state reading module 101 is used to execute S1 in claim 1. The neutral state management module 102 is used to store or form neutral number density, neutral velocity, neutral momentum, neutral energy, neutral temperature, neutral discrete carrier, neutral transport envelope, and neutral state square. The process closure quantity, pre-ionization initial state, neutral particle injection beam state, cross-pulse inheritance state, wall recycling inventory state, or molecular neutral component state are selected from one or more of the following: the ionization and collision rate forming module 103 is used to execute S2; the neutral side update module 107 is used to execute S3 and form neutral transport flux and neutral side pending acceptance update; the particle exchange closure module 104, momentum exchange closure module 105, and energy exchange closure module 106 are used to execute S4; the plasma source term access module 108 is used to execute S5 and S6; and the synchronization consistency acceptance module 109 is used to execute S7.

9. An electronic device, characterized in that, It includes a processor and a memory for storing processor-executable instructions; the processor is configured to invoke the instructions stored in the memory to perform the method of any one of claims 1 to 7.

10. A computer-readable storage medium or computer program product, characterized in that, The computer-readable storage medium stores computer program instructions, or the computer program product includes a computer program or instructions; when the computer program instructions, computer program, or instructions are executed by a processor, they implement the method of any one of claims 1 to 7.

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